4.8. Input/Output Description

Table 4.8.1 contains a listing of SAS4A/SASSYS‑1 input locations that are relevant to the point kinetics and reactivity feedback models. Table 4.8.2 contains a listing of input locations that are relevant to the new decay heat model. A complete description of all SAS4A/SASSYS‑1 input may be found in Section 2.8.2.

The new decay heat model is compatible with old input decks. However, to support the larger number of terms in the ANS standard as well as specifying multiple curves within a single decay heat region, new input locations have been specified. The new decay heat model still supports a total of 5 user-supplied decay heat curves, but also supports up to eight built-in standard curves. (Currently, only four are defined by the code.) A total of 10 decay heat regions can be defined using any combination of decay heat curves. User-supplied integer input for the decay heat model is contained in Block 1 (INPCOM). Floating-point input is contained in Block 12 (POWINA).

The simplest usage of the new decay heat model is one that takes advantage of the built-in standard curves. For example, a problem with a single decay heat region that can be characterized by the decay heat from U-235 fission requires only two input parameters: NDKGRP = 23 and DKANSI(1,1) = 1.0.

In addition to the decay heat input described below, the channel-dependent input parameter IDKCRV must be specified to indicate which decay heat region each channel belongs. If this value is zero, no decay heat will be calculated for that channel, and power from the predefined non-decay-heat region will be used. Similarly, the association of bypass channels with decay heat regions is defined by IDKTYP.

On each main time step, the following quantities are printed: a) total reactor power (normalized to unity at time zero), b) decay-heat power, c) integrated energy (full-power seconds), d) net reactivity, e) programmed reactivity, f) control rod drive expansion reactivity, g) Doppler reactivity, h) fuel and cladding axial expansion reactivity, i) coolant reactivity, j) fuel-motion reactivity, and k) cladding-motion reactivity. In addition, the coolant, fuel, cladding, axial expansion and Doppler reactivity for each channel are also printed at each main time step. This information is also printed following each major print in expanded form (more significant digits), along with the group-wise values of the delayed-neutron precursor concentrations and decay-heat powers.

Table 4.8.1 Point Kinetics and Reactivity Feedback Input Data
Symbol	Reference	Name	Block	Location	Suggested Value
-	-	IPOWER	1	8	0 or 1
-	4.11.1	IPOWOP	1	9	0 or 1
-	-	NPK	1	10	0
-	-	NDELAY	1	16	≥0, ≤6
-	-	NPREAT	1	18	≥0, ≤20
-	-	ICREXP	1	31	≥0, ≤3
-	-	IDBPWI	1	35	0 or 1
-	-	IRADEX	1	36	≥−7, ≤7
-	-	NFUELD	1	39	<0
-	-	NOREAC	1	41	≥0
-	-	NSRMTB	1	43	Not used.
-	-	NSUBTC	1	51	≥0
-	-	MTGRD	1	52	1 or 2
-	-	MTACLP	1	53	1 or 2
-	-	MTTLP	1	54	1 or 2
-	-	MODEEX	1	55	≥0, ≤3
-	-	JREEXT	1	56	0 or 1
-	-	IREACT	1	58	≥−2, ≤2
-	-	NSUBTR	1	59	≥0
-	-	NRRNGS	1	60	0,1, or 2
-	-	MTRRAC	1	61	1 or 2
-	-	MTRFAC	1	63	1 or 2
-	-	MTRFT	1	64	1 or 2
-	-	IROPT	1	65	0 or 1
-	-	JCRIND	1	66	>0
-	-	ICRDDB	1	71	0,1, or 2
-	-	ICRTMP	1	72-74	≥0
-	-	ICRNOD	1	75-77	-
-	-	NSEGCR	1	78	>0
-	-	MTCB	1	81	1 or 2
-	-	KDEBUG	1	82	0 or 1
-	-	KEBRS1	1	83	≥0
-	-	KEBRS2	1	84	≥0
-	-	IDBDKH	1	85	-
-	-	NULLD3	1	86	-
-	-	NOFDBK	1	89	≥0
-	-	IBOWTP	1	102	0 or 1
-	-	KCHUIS	3	1209-1242	Not used.
-	-	NRREAC	3	1292	≥0
-	-	ISLREA	3	1293-1300	≥0
-	-	LBYP	3	1301	≥0
-	-	LELBYP	3	1302-1309	≥0
-	-	EPSPOW	11	3	\(10^{- 4}\)
-	-	ASCRAM	11	23	Not used.
-	-	PSCRAM	11	24	Not used.
-	-	GSCRAM	11	25	Not used.
-	4.11.1	POW	12	1	-
\(\Lambda\)	Eq. (4.2-4)	GENTIM	12	2	-
-	4.11.1	POWTOT	12	3	-
\(\beta_{\text{i}}\)	Eq. (4.3-1)	BETADN	12	4-9	-
\(\lambda_{\text{i}}\)	Eq. (4.3-1)	DECCON	12	10-15	-
-	-	OLDBDK	12	16-21	Not used.
-	-	OLDDKL	12	22-27	Not used.
-	-	OLDBDT	12	28	Not used.
-	-	PREATB	12	29	-
-	-	PREATM	12	49	-
-	4.11.1	FRPR	12	69	-
\(L_{\text{cr}}\)	Eq. (4.5-45)	CRDLEN	12	71	-
\(\alpha_{\text{cr}}\)	Eq. (4.5-45)	CRDEXP	12	72	-
\(a_{\text{cr}}\)	Eq. (4.5-48)	ACRDEX	12	73	-
\(b_{\text{cr}}\)	Eq. (4.5-48)	BCRDEX	12	74	-
\(M_{\text{cr}}C_{\text{cr}}\)	Eq. (4.5-38)	CRDMC	12	75	-
\(h_{\text{cr}}A_{\text{cr}}\)	Eq. (4.5-38)	CRDHA	12	76	-
\(V_{\text{ui}}\)	Eq. (4.5-39)	UIVOL	12	77	-
\(C_{\text{re}}\)	Eq. (4.5-23)	RDEXPC	12	78	-
\(\frac{{\text{XMC}}}{{\text{XAC}}}\)	Eq. (4.5-23)	XMCXAC	12	79	-
-	-	SCRTAB	12	80	Not used.
-	-	SCRTME	12	90	Not used.
-	-	PRETB2	12	100-179	-
-	-	PRETM2	12	180-259	-
\(S_{{\text{GRMAX}}}\)	Eq. (4.5-27)	SLLMAX	12	408	-
-	-	PITCHG	12	409	-
-	-	PITCHA	12	410	-
-	-	PITCHT	12	411	-
-	-	RDEXCF	12	412	-
-	-	TLPRRC	12	413	-
-	-	BNDMM1	12	414	-
-	-	BNDMM2	12	415	-
-	-	TINSRT	12	416	-
-	-	REAINS	12	417	-
-	-	TLIMIT	12	418	-
-	-	DFLTCS	12	419	-
-	-	DFLTSS	12	420	-
-	-	ACLPRC	12	421	-
-	-	FCDTR1	12	422	-
-	-	FCDTR2	12	423	-
-	-	FCDTRF	12	424	-
-	-	DRCOLL	12	425	-
-	-	CRSAC	12	426	-
-	-	RR1TC	12	427	-
-	-	RR2TC	12	428	-
-	-	RODID	12	429	-
-	-	RODOD	12	430	-
-	-	SHRDLN	12	431-433	-
-	-	SHRDID	12	434-436	-
-	-	SHRDOD	12	437-439	-
-	-	RHOCRD	12	440	-
-	-	HTCPCR	12	441	-
-	-	CONDCR	12	442	-
-	-	VFCRD	12	443	-
-	-	HFILM	12	444	-
-	-	FLSHRD	12	445	-
-	-	AREACR	12	446	-
-	-	FLOEXP	12	447	-
-	-	ACLPEL	12	448	-
-	-	TLPEL	12	449	-
-	-	PTCHRA	12	450	-
-	-	PTCHRT	12	451	-
-	-	RCBARR	12	452	-
-	-	FCDTCB	12	453	-
-	-	CB2TC	12	454	-
-	-	YKNF	12	455	-
-	-	YKHF	12	456	-
-	-	YKNNA	12	457	-
-	-	YKNSS	12	458	-
-	-	YRCUR	12	459	-
-	-	YRCLR	12	460	-
-	-	YRCRR	12	461	-
-	-	YRCCR	12	462	-
-	-	YRCGP	12	463	-
-	-	YRCDOP	12	464	-
-	-	YDELT0	12	465	-
-	-	YABOW	12	466	-
-	-	YBBOW	12	467	-
-	-	FCR	12	468	-
-	-	YTCUT	12	469	-
\(\varepsilon_{\text{ex}}\)	-	EXPCOF	13	1263	-
-	-	IAXEXP	51	181	0, 1, or 2
-	-	IDKCRV	51	203	≥0, ≤5
-	-	ICHUIS	51	362	0 or 1
-	-	IPOWRZ	51	364	0 or 1
-	-	IREACZ	51	365	0 or 1
\(\gamma_{\text{s}}\)	Eq. (3.3-23)	GAMSS	62	2	-
\(\gamma_{\text{c}}\)	Eq. (3.3-23)	GAMTNC	62	4	-
\(\gamma_{\text{e}}\)	Eq. (3.3-23)	GAMTNE	62	5	-
\(\overline{P}\)	4.11.1	PSHAPE	62	6-29	-
\(P_{\text{r}}\)	-	PSHAPR	62	30-44	-
\(\alpha_{\text{D}}\)	Eq. (4.5-2)	ADOP	62	62	-
\(\alpha_{\text{D}}\)	Eq. (4.5-2)	BDOP	62	63	-
-	-	WDOPA	62	64-111	-
\(\left( \rho_{\text{c}} \right)_{\text{jI}}\)	Eq. (4.5-22)	VOIDRA	62	112-159	-
\(R_{\text{e}}\)	-	CLADRA	62	160-207	-
\(R_{\text{f}}\)	Eq. (4.5-20)	FUELRA	62	208-255	-
-	4.11.1	PRSHAP	62	256	-
-	-	PSHPTP	62	257-261	-
-	-	PSHPBT	62	262-266	-
-	-	XRFSHP	62	268	-
-	-	XRNSHP	62	269	-
-	-	XRSSHP	62	270	-
-	-	PSHAPC	62	271-318	-
-	-	PSHAPB	62	319-366	-
\(\alpha_{\text{f}}\)	Eq. (4.5-4)	FUELEX	63	73	-
\(\alpha_{\text{e}}\)	Eq. (4.5-5)	CLADEX	63	74	-
\(Y_{\text{f}}\)	Eq. (4.5-8)	YFUEL	63	75	-
\(Y_{\text{e}}\)	Eq. (4.5-8)	YCLAD	63	76	-
\(\varepsilon_{\text{ex}}\)	Eq. (4.5-21)	EXPCFF	63	79	-

Table 4.8.2 Decay Heat Input Data
Symbol	Reference	Name	Block	Location	Comments
-	Eq. (4.4-19)	NDKGRP	1	17	max = 24
-		NPOWDK	1	45	max = 5
-		NPDKST	1	46	max = 8
\(\beta_{\text{n}}\)	Eq. (4.4-4)	BETADK or DKBET2	12	260-289 511-630	deprecated, use DKBET2
\(\lambda_{\text{n}}\)	Eq. (4.4-1)	DKLAM or DKLAM2	12	290-319 631-750	deprecated, use DKLAM2
\(\beta_{\text{d}}\)	Eq. (4.4-4)	BETAHT	12	320-324	-
\(x_{\text{i}}\)	Eq. (4.4-12)	DKFRAC	12	751-800	-
\(x_{\text{i}}\)	Eq. (4.4-12)	DKANSI	12	801-880	-
\(P_{\text{t}}^{k}\)	Eq. (4.4-19)	POWLVL and PWLVL2	12	325-364 881-920	PWLVL2 is an extension of POWLVL
\(\tau_{\text{k}}\)	Eq. (4.4-19)	POWTIM and PWTIM2	12	365-404 921-960	PWTIM2 is an extension of POWTIM
\(Q_{\text{t}}\)	Eq. (4.4-2)	QETOT	12	961-968	default = 200 MeV