Impact of H in H₂O thermal scattering data on depletion calculation: k_∞, nuclide inventory and decay heat

Abstract

The impact of the H in H2O thermal scattering data are calculated for burnup quantities, considering models of a UO2 pincell with DRAGON and SERPENT. The Total Monte Carlo method is applied, where the CAB model parameters are randomly varied to produce sampled (random) LEAPR input files for NJOY. A large number of burnup calculations is then performed, based on the random thermal scattering data. It is found that the impact on k∞ is relatively small (less than 35 pcm), as for nuclide inventory (less than 1% at 50 MWd/kgU) and for decay heat (less than 0.4%). It is also observed that the calculated probability density functions indicate strong non-linear effects.

On the estimation of nuclide inventory and decay heat: a review from the EURAD European project

“…-17 PIE samples were used to calculate nuclide compositions, uncertainties, and biases, for 4 ARIANE samples (GU1, GU3, BM1, BM3), 8 ENRESA samples (not available in SFCOMPO), the U1 PROTEUS sample (also not available in SFCOMPO), 2 Takahama samples (SF95-4 and SF95-5), and 2 Gundremmingen samples (B23-A1-I2680 and C5-B23-K2680), with the addition of 2 computational cases (S1.PWR and krsko.PWR [14,15]), -271 calorimetric measurements from CLAB (labelled herein as CLAB-2006), GE-Morris, HEDL facilities and the "SKB-Vattenfall" blind test were analyzed for the assembly average decay heat [16][17][18][19], and the decay heat from the 17 (not measured) PIE samples. Detailed studies were independently published for a number of cases, see references [20][21][22][23][24][25][26][27][28][29][30][31][32]50]; summaries are presented in Tables 1 and 2. Regarding sensitivity studies presented in Table 1, considerable efforts have been made to address the effect of the irradiation history, as-built manufacturing data and effect of various calculation model approximation on the SNF characterization.…”

“…-The first remark is that generally speaking, nuclear data is the largest contributor to uncertainties on nuclide concentrations (cross-sections and fission yields; the impact of thermal scattering data was shown to be negligible [21]). The only noticeable exceptions are 239 Pu, for which the moderator temperature can be almost as important as nuclear data in the case of PWR samples, and 235 U, 239 Pu and 241 Am for which the void coefficient is also an important source of uncertainties for BWR samples.…”

Spent nuclear fuel management, characterisation, and dissolution behaviour: progress and achievement from SFC and DisCo

“…For decay heat, the calorimetric measurements from CLAB (Swedish Central Intermediate Storage Facility), GE-Morris, and HEDL (Hanford Engineering Development Laboratory) were considered, leading to more than 250 cases. To support the recommendations of this subtask, some studies were already published, see references [3][4][5][6][7][8][9][10][11][12][13][14][15]. A global review of the The aim is to produce NDA systems that can be used to provide experimental data to validate the performance of the codes (including nuclear data) and to verify the declared design and operational history of the assemblies.…”